Are Eggshells Good for Plants? Garden Pros Weigh In

Whether you have an outdoor garden filled with flowers like hydrangeas, a veggie garden, or you’re just trying to keep that lone fern in your living room alive, it’s fair to say plant parents everywhere are always looking for new ways to make their plants grow and thrive. Has your latest trip to your local garden center or nursery left you feeling out of options? One trick you might have heard of is using eggshells in your plant’s soil. But does this actually work? Here’s what you need to know according to the experts.

Are Eggshells Good for Plants?

Yes, eggshells can be beneficial for some plants. Palm Street seller Cheyan DuVal says, “Eggshells contain a lot of calcium, which is a crucial nutrient for a lot of plants, and can help neutralize the acidity or pH of the substrate.”

However, this doesn’t mean you should just insert eggshells into a plant’s pot or soil after making your morning omelet. The Sill’s plant expert, Paris Lalicata, explains, “Eggshells take time to break down and allow the calcium to become available, so it’s not a quick fix.”

Before preparing your eggshells (it’s a little bit of a process), you should first see if your plant can actually benefit from additional calcium. Lalicata notes that garden plants that produce fruit, such as tomatoes, can benefit from eggshells. On the other hand, houseplants don’t really need extra calcium, because standard all-purpose potting mix generally provides enough nutrients.

How to Prepare Your Eggshells

“If you do decide to add calcium via eggshells, one route is to first sanitize the shells (the risk of salmonella is low but not worth the risk!) by baking them in the oven at a low temperature,” says Paris. “Then grind them into a fine powder (a coffee grinder usually does the trick) to work into the soil around a plant’s roots. Over time, the plant will take up the nutrients.”

After grinding the shells, be sure to wash your coffee grinder and sanitize it (yes, even if you’ve baked your shells) by cleaning it in the dishwasher. Most coffee grinder parts go on the top rack.

Do Any Other Food “Leftovers” Benefit Your Plants?

In addition to eggshells, you might have heard that banana peels can benefit your plants. But much like eggshells, you can’t just throw your used banana peel over your soil and expect results. “While banana peels are rich in potassium and contain small amounts of nitrogen and phosphorus, all things plants like, simply leaving a peel to rot in your dirt isn’t helpful,” explains Lalicata. “The peel has to break down (decompose) in order for those nutrients to become available in a way that’s useful to the plant. And the process of decomposing takes time and doesn’t happen in isolation.”

How To Give Your Plants Extra Nutrients

If you want to feed your plants, Lalicata recommends using fully processed compost and fertilizers designed specifically for your plant’s needs. These are far better options than both eggshells and banana peels.